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SPACECRAFT APPROACHES VENUS: A Japanese spacecraft named "Akatsuki" is approaching Venus on a mission that planetary scientists say could end up teaching us a great deal about Earth. Get the full story from Science@NASA.
GREEN SNOW: Tonight's weather forecast in Antarctica calls for a 35% chance of green snow. Yes, green. It turns that color during geomagnetic storms, as shown in this August 1st photo from Nick Roden of Australia's Davis Station on the Antarctic coast:
"We've had some fantastic aurora displays lately--bright enough to reflect from the snow," says Roden. In addition to the green auroras, there is also a green laser lancing up from the research station in the background. "That's our LIDAR, which we use to study the upper atmosphere."
A new episode of green may be in the offing. A coronal mass ejection (CME) is expected to deliver a glancing blow to Earth's magnetic field on Aug. 17th or 18th, and NOAA forecasters estimate a 35% chance of polar geomagnetic activity when the cloud arrives.
August 2010 Northern Lights Gallery
[previous Augusts: 2009, 2008, 2007, 2006, 2005, 2004, 2003]
BIG PERSEID: The vast majority of meteoroids that hit Earth's atmosphere during last week's Perseid meteor shower were mere specks of comet dust, massing no more than a fraction of a gram. This one was a big exception:
"The University of Western Ontario network of all-sky cameras captured this Perseid on August 13th," says Bill Cooke of NASA's Meteoroid Environment Office. "It weighed in at about 1.5 kilograms." The 14-cm comet chunk hit Earth's atmosphere at 140,000 mph, creating a flash of light about as bright as a quarter Moon. "Now that was a Perseid!"
"There is another somewhat dimmer Perseid fireball just below it," points out Cooke. "It massed only 2 grams--but that was still enough to make a flash as bright as Venus. In this one image," he marvels, "we see two meteoroids with a mass ratio of 750:1."
More Perseids, big and small, may be found flitting through the gallery.
2010 Perseid Photo Gallery
[meteor radar] [Perseid fireball cam]